Re: Zoomable Number Line

As I zoomed in there was a slight left drift of the numbers, so that, although I had started centred on zero, I became centred on 3.4, then 3.45 and so on.

Just tried it again. Aaarrhh, the light dawns. It depends where I'm pointing on the number line; it zooms out from that point. That's good. Better than in my dream. But maybe it needs an instruction for dumb-brains like me who take ages to work it out.

After 3.450 I had no more resolution to see further digits, although the power of ten count must still have been working .... if I zoomed out, say, another 5 powers of ten, to zoom back took 5 zoom levels again before I was back to where I'd been. This is obviously always going to be a problem as there'll always be a point beyond which you cannot go.

..... Unless, and I'm not sure about this, only every other number is displayed to free up space; then every fifth number ....... Not sure if that would be a solution. Even then a limit point would be reached where the displayed numbers were off the screen and all that would be left would be the line.

So maybe just come up with a "You've reached the limit" notice and then stop zooming. Either way, I don't think it helps with understanding if the digits all start to look like the same number. So perhaps stick at say 6 character width numbers and lock the zoom after that. (But still track left and right with the arrows.)

I can picture learners just liking to operate the zoom and being fascinated by the result. Not realising that they are seeing and learning about the number system in action. Great!

Bob

ps. Shed in bits and moved. Now all I've got to do is put it back together again!!

Children are not defined by school ...........The FonzYou cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Re: Zoomable Number Line

hi MIF and bobbym,

More digits yes, but less numbers perhaps.

If you look at the three screen shots below, taken a few seconds after each other, the numbers are looking a bit crowded, then they spread out and are easily readable, then they get crowded again. Also, in the third shot, there should be another digit showing, but there isn't, so presumably you've got a 'number of characters showing' limit.

How about an algorithm that divides the space available by the number of digits that 'want to be shown according to that power of ten' , to arrive at the optimum amount of numbers so that all their digits will show?

Then, as the powers of ten get more negative, less numbers will show, but to a greater precision. So bobbym gets his wish as the screen fills with more and more 9s (see 4th fiddled screen shot).

I know you enjoy a challenge.

Bob

ps. Hands suffering from too much gripping and twisting. Just been to get some new timber for the base ... old stuff was rotten. Started to construct new base. Chicester would be proud of me.

Last edited by bob bundy (2011-10-22 00:58:07)

Children are not defined by school ...........The FonzYou cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Re: Zoomable Number Line

Whoa! I was just being funny with the crack about the .999999999... and needing more digits. I love digits and love seeing them but what was your original idea when you started on this one? Implement that!

A bit of advice: Stop listening to that bobbym fella, check with me first before you do anything he says.

In mathematics, you don't understand things. You just get used to them.If it ain't broke, fix it until it is. Always satisfy the Prime Directive of getting the right answer above all else.

Re: Zoomable Number Line

Just an update to let you know I am still working on this as time permits. I am trying to move some of the calculations to Full Precision as the rounding errors look really bad, but that is not as easy as it may sound.

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

Re: Zoomable Number Line

hi MIF,

Well thanks for keeping going. I have every confidence.

Shed update. Had to get the roof on before it rained so Monday was hectic and I was on the roof fixing in wooden slats to hold the felt until it was too dark to see the nails any more. Tuesday, spent the day at my Mother's sorting out her garden. Today finished the slats but rain stopped play. So no final picture yet. Hopefully tomorrow.

Off to see Dave Gorman tomorrow evening. Wow, life is very busy when you're retired!

Really stuck on Juan's integral. I think it's directly integrable for the right choice of 'u' and 'v' in a quotient. But my paper attempts are full of near misses. About to start Version 5.

Bob

Children are not defined by school ...........The FonzYou cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei